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We have CS3000 DCS using ALP111 interface with SIMOCODE PRO C Starters and are suffering from Spurious trips from time to time. Based on analysis by Profibus n/w specialists baudrate set at DCS and SIMOCODE end seems to be on higher side (1.5kbps) and SIMOCODEs are not able to respond within a stipulated time period.
As a short term action baudrate brought down to 187.5Kbps and found significant improvement. As a long term action recommended by auditor introduced procentec n/w hubs and ensured siemens fast connect cables and connectors in addition to maintaining the cable looping/ spacing.
Of late again the same problems repeated and while checking it came to know that DCS Equipment and SIMOCDES are connected to a Non isolated Earthing circuit (Connected to Plant Equipment Earth) and we suspect this also could be a contributing factor. As i understand that Yokogawa DCS systems require an isolated Earth (<100ohm independent grounding from other Equipments) though. what could be the recommendations/guide lines from International Standard bodies if different systems interfaces through profibus like n/w.
Someone pl. reply to me ,
[email protected]
As a short term action baudrate brought down to 187.5Kbps and found significant improvement. As a long term action recommended by auditor introduced procentec n/w hubs and ensured siemens fast connect cables and connectors in addition to maintaining the cable looping/ spacing.
Of late again the same problems repeated and while checking it came to know that DCS Equipment and SIMOCDES are connected to a Non isolated Earthing circuit (Connected to Plant Equipment Earth) and we suspect this also could be a contributing factor. As i understand that Yokogawa DCS systems require an isolated Earth (<100ohm independent grounding from other Equipments) though. what could be the recommendations/guide lines from International Standard bodies if different systems interfaces through profibus like n/w.
Someone pl. reply to me ,
[email protected]